BEIJING -- China has shriveled its coal imports from North Korea to zero for three months until May as part of efforts to implement sanctions on the North adopted by the UN Security Council, Chinese customs data said Tuesday.

The data showed there were no coal imports from North Korea in May but were sharp increases in coal imports from Indonesia, Mongolia and Russia.

China suspended all coal imports from the North in March and April in an embargo that is set to remain in place for the rest of the year. 

The suspension is expected to hit the North Korean economy, given that North Korea relies on China for more than 90 percent of its coal trade, which, along with iron ore, takes up more than 40 percent in China-North Korea trade.

The resolution put an upper limit on the North's coal exports at $400.9 million, or 7.5 million tons per year, whichever is lower, starting on Jan. 1.

In comparison to the decrease in coal imports from the North, China's coal imports from Indonesia and Mongolia rose 23 percent and 42 percent, respectively, from the same month last year to 3.86 million tons and 3.16 million tons in May.

During the reported month, China's coal imports from Russia showed a two-fold increase from a year earlier to 490,000 tons. (Yonhap)